Russia claimed the West, Kyiv ordered the Moscow terror attack. Now it has the problem of proving it CNBCUkraine war live updates: Russia says it’s ‘hard to believe’ Islamic State group behind terror attack; death toll rises to 140 CNBCRussia says it’s hard to believe Islamic State could have launched Moscow attack Yahoo! VoicesVladimir Putin blames ISIS and Ukraine for Moscow concert attack USA TODAYRussia says suspects in Crocus concert hall attack detained as death toll rises to 137 CNN